DROP ROLE autosystem;
DROP ROLE distro;
select * from pg_user;

exm.
postgres=# select * from pg_user;
  usename   | usesysid | usecreatedb | usesuper | usecatupd |  passwd  | valuntil | useconfig
------------+----------+-------------+----------+-----------+----------+----------+-----------
 pgsql      |       10 | t           | t        | t         | ******** |          |
 postgres   |    16384 | t           | t        | t         | ******** |          |
 autosystem |    16387 | f           | f        | f         | ******** |          |
 distro     |    16388 | f           | f        | f         | ******** |          |
(4 registros)

postgres=#

blz